Dual booting netbsd and windows 2003 server

I have two hard disks in my pc and installed windows 2003 server on one and netbsd on the other. I can currently boot to both OS's, however, to boot to netbsd i must hold the f12 key during the boot process to select which hard disk it is on. If i let the boot process take its normal course it will only boot to windows server. I would like to set-up a menu select at the start of the boot process so that i can select which OS to boot. Any help would be most appreciated.